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How To Approach Setting Up A Car?


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#1 atumno

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Posted Sep 18 2013 - 05:51 PM

Hello everybody.

I've been away from simracing for quite some time now and I still won't be able to spend a particularly lot of time with it for some time being. I still like to cruise some laps occasionally, but I cannot practice regularly anymore. I'm not even remotely fast enough to think about running a race. However, whenever I try to achieve some decent laptimes it becomes obvious that I never really got the grips on setting up a car. Plenty of setup guides are available, and for a lot of settings i more or less understand what they do, but how do I decide on what particular setting to tune?

If my car understeers, do I go for rollbar or springs/dampers, do I go to front or rear axis?
How will my decision differ if it happens on corner entry/mid/exit?
How will I ever be able to stabilize the car under breaking?...

And, probably most important, while driving: how do I learn to become aware of the little details that need to be noticed to get a proper understanding of the car's behavior? On what details would I focus my attention at what time? How do I find the setting that needs to be tuned to maybe become a little quicker in a particular spot on the track? Without all the tangible feedback of actually sitting in the car?

Since I usually only can run for some limited time I tend to get impatient, I need to learn how to do all this in an effective way. If a real life driver has mechanics and engineers to discuss what changes are to be done, how can I do these things at all?



I will be grateful for any advice here.

#2 jklhill

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Posted Sep 18 2013 - 06:38 PM

I find this helpful; http://www.racingont...handling-guide/ and http://srmz.net/inde...t=0

This one is for Nascar 2003 put still usefull; http://www.zagerdesi...setup_guide.htm

Sorry I can't help with the patience or lack of :idunno:

#3 JMF

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Posted Sep 18 2013 - 06:40 PM

View Postatumno, on Sep 18 2013 - 05:51 PM, said:


If my car understeers, do I go for rollbar or springs/dampers, do I go to front or rear axis?
How will my decision differ if it happens on corner entry/mid/exit?
How will I ever be able to stabilize the car under breaking?...


a) If it understeers soften the front springs or front roll bar. I usually keep the roll bars about even and use the spring rates to balance the car the way I want.

B) I can't remember. I fooled with this a long time to carry as much speed as possible through the Ascari bend at Monza. I made some improvements using the bump or rebound, can't remember which.

c) Braking is my weakest point in GPL. I try to make the front lock slightly before the rear and brake earlier.

#4 jgf

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Posted Sep 18 2013 - 07:40 PM

I use the shocks for grip and the bars for balance.  On a tight, twisty, bumpy course (Nurburgring, Machwerk, etc.) you want softer shocks to keep the tires in contact with the road;  on smooth, flat tracks (Monza, Silverstone) you want stiffer shocks to maintain the car's attitude.  I adjust all four shocks proportionally, keeping the ratio of front/rear as best as possible.  I like the front bar as small as possible while maintaining steering stability;  if you're overcorrecting frequently, especially on corner exit, the bar is too small (if the car is fishtailing wildly and you're sawing the wheel back and forth until, usually, you spin out, the front bar is definitely too small).  Once happy with steering response, I use the rear bar to balance the car.  Generally, if the car feels too twitchy the suspension is too hard for the track, if it feels sluggish and unresponsive the suspension is too soft.  Springs are an integral part of the cars physics, designed to carry the weight of the car on the suspension;  unless I feel the default values are incorrect (GPL ...and P&G.. is the only sim where I actually trust mod designers) I only adjust springs as a last resort.

Brake balance is also important, and if not set correctly can ruin an otherwise good setup.  Fortunately it's fairly easy to adjust in GPL (thanks to the forgotten soul who recommended this years ago on RSC) - go to a long straight, such as Monza, and accelerate; near the end hit the brakes strongly but smoothly til you hear tire squeal, exit and view the replay from above.  Which tire left the skid mark?  Adjust the bias one click towards the other end of the car and try again.  You'll never get all four wheels to lock evenly but this is easier and faster than trying to balance the brakes while running laps (any subsequent setup changes which shift the balance will necessitate doing this again).

In general, and this is a very broad generalization, front end settings affect turn in more (when you need precise steering) and rear end settings affect exit more (when you are getting on the power).  The trick when driving is to have this transition occur exactly at the corner apex;  this is also an area where the number of clutches comes into play as they control how quickly the differential transitions from coast to power.  If you find the car very "nervous" or unpredictable near the apex, try using one less clutch.

The lack of tactile input is, for me, the most difficult part of simracing.  In the real world I could tell, subconsciously, from the vibrations, body roll ,etc. what each wheel was doing;  in a sim you rely mainly on visual cues of how the car is oriented on the track when you have difficulties.  Take a corner slightly too fast and if the car slides smoothly sideways it's well balanced (this is the basis of "four wheel drift");  but it's easy to misdiagnose a strong understeer as oversteer - you turn the wheel more and more into a corner and suddenly you spin, automatically assuming oversteer when in actuality the front wheels weren't getting grip, eventually you turn them to such an angle that their lateral grip takes over and you have immediate oversteer.  With practice you learn what to watch.

A good way to learn setup adjustments is to pick a car and track you are comfortable with, and a stable setup.  Don't try for hotlaps, just get the tires warm then try for consistent laps, you want to learn how the car feels and reacts throughout the lap.  Now go to the garage and change one thing - perhaps stiffen the front shocks one click or change a bar one click - then go out and try for consistent laps again.  Return to the garage, undo that change, change a different setting, and back to the track.  An evening of this and you'll get a good idea of how each item affects the car's handling.

When creating a setup remember that all are compromises, you will never get one that works equally well everywhere on the track.  So when you find that corner, or combination of corners, where you are not happy with the handling ... forget about it;  optimize the setup for the rest of the track and accept there's one spot where you "tiptoe".

Edited by jgf, Sep 19 2013 - 01:42 AM.


#5 Art-J

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Posted Sep 19 2013 - 03:14 AM

Don't want to sound rude, but If You have a limited amount of time to spend on simracing nowadays, You probably are a bit short on lap consistency as well. It's difficult to judge result of small setup adjustments if Your laptimes are all over the place (especially when one has to spend quite a while on changing and testing one parameter at a time, as described above).

Nevertheless, some basic "tips & tricks" on springs, shocks, bars and general car behaviour might come in handy and the guys above surely provide some of these!

#6 atumno

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Posted Sep 19 2013 - 09:26 AM

thanks everyone for your help.
I already know the guides posted above, i have used them, but often enough when i start fiddling with one setting I can't help feeling that i might have take the wrong approach...

Art-J - no problem, nothing rude there, you're remark is not wrong. I usually try to go for consistency as much as possible before starting to find some speed (but obviously my consistency has declined); being in control and as relaxed as possible is more important than speed to me; besides the consistency issue I want to have fun and not to put myself under more stress than neccessary...

jgf - that's very useful compressed information, quite what I was looking for, I soon will have a go for these, thanks.
One question came to my mind: When I run an experimental session as you did suggest (I have tried it, but I still am unsure about all of this), is a single click a sufficient amount of change to feel the difference? Would it be reasonable to try large changes to feel a radical difference or will that just obscure the use of that setting?

One other issue I forgot to mention before is the general approach to adjusting suspension; as I understand it as soon as i adjust the springs I have to adjust the dampers accordingly (and vice versa) - how do I do that sanely and how do I know I'm not dialing in ridiculous combinations?...
Is it neccessary to watch the combinations of roll bar and spring/damper settings in the same way? Do I have to go for soft suspension and soft rollbar at the same time or can a combination of stiff suspension ans soft rollbar (or whatever else) make sense?

#7 John Woods

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Posted Sep 19 2013 - 10:50 AM

Olah, Atumno!

So little time, do you have enough to implement the answers?

According to BrunoB, (for reference), if your car understeers, it is short on grip in the front, so you want to soften the front until it quits skiding out from under itself. If it oversteers there are two things to consider. 1) there is not enough grip on the rear, and 2) the car is steered by throttle-induced oversteer caused by the weight shift of sprung weight resting asymmetrically on un-sprung weight.

Here's my strategy:(As usual, its all questions and guesses, and well aware others will definitely not agree).

Hold most setup variables constant. This zeros them out as dynamic variables, (used to tweak a car for a specific track). In my instance, the following are pretty much always the same for any track: brake bias (58%F), front springs 3-pounds softer than rear, zero camber, .05 front toe, 16F/18R tire pressure, 30/30/6 diff and shocks at 4/2F and 4/1R, although lately its tended to 4/3F and 4/2R. If you change a constant all other factors are effected and so, must be adjusted to accomodate.

In general, (for me), there are three basic setups, one for tracks like Spa/Monza, (stiff, long haul top end with 270 fronts), one for Nurburgring, (way looser and up to 190mph briefly with 100mph 3rd gear average and 170mph in 4th, front springs at 260), and one for Monaco, (real loose and softest, up to 180mph, 1/2nd gear tweaked for no-shifting two-blast run down from Mirabeau and front springs at 255).

For the first thing to consider, soften springs, (not shocks or bars) to compensate for skid-effect loss of grip, so overall grip is increased. (At 16F/18R tires are already soft enough).

Tire note: Analysis has revealed optimum grip for Grand Prix Legends 67s is acheived when pressures are at 24F/26R when at operating temps, (which I've forgot). According to reliable sources, 16F/18R cold was once a real racing standard, so after experimenting with it for awhile got used to it and lost interest in testing it.

For the second, (steering with throttle-induced oversteer), for a given diff and shock setup, chassis-effect oversteer is caused by its weight shift between centered at neutral, (with at best 25% of weight on each wheel), to the outside wheels on a turn. Turns out, it doesn't all go to the outside unless a poor setup and/or the driver lets it, but if it doesn't go far enough there is less opportunity to control steering with the throttle, that is, less range of motion of the chassis within the limits of grip, and less grip. The farthest the chassis should go is just enough to effect maximum grip on the outside tires. But if it doesn't go that far, the car is slower than it should be, so not out far enough is not good either.

Currently, with 5:1 or 7:1 steering, the front bars are around 260 and rear bars around 390.

So, because everything else is tight, (my theory), all the oversteer is caused by and controlled by throttle twisting the bars.

For the throttle to control steering, and get the car to furn inward while on an outside vector, the rear has to go farther out than the front without losing grip and the front has to stay where it is.To maintain throttle-induced oversteer, the car must be turned into the camber of the track and hold itself there without steering wheel motion. (So the driver, for instance, is "steering left" while the car turns right). This is all about tuning the front and relying on force feedback and tire sounds. If there's tire sound, btw, you are near the limit of maximum grip, which is good if your car is setup properly.

If the car understeers and sinks into the track, (push), slightly stiffen the front springs and slightly soften the rears, slightly decrease front bar and increase the rear the same amount...test until symptom goes away.

If the car turns-in too quickly, stiffen the front bar without changing the rear. It the car doesn't turn-in but doesn't lose grip and doesn't sink-in, decrease the front springs and bar and increase the rear bar but not the springs.

In general, once all other factors are neutralized for a given driver display and accurate POV, the only things changed from track to track are the transmissions and anti-roll bars, then maybe accommodation for a special case like a particular slope the springs can't handle.

It is not about what it should be. Its about making it do what you want.

Edit: No, I don't think you adjust shocks just because you changed springs. Adjust things because of what's happening while on the track. Note my idea is hold some things constant and only tweak others (mainly on the bars) as required to suit. In general seems looser setups, (more range of throttle-controlled oversteer), are capable of helping to create faster laps.

Edited by John Woods, Sep 19 2013 - 02:18 PM.


#8 jgf

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Posted Sep 19 2013 - 03:36 PM

View Postatumno, on Sep 19 2013 - 09:26 AM, said:

...
One question came to my mind: When I run an experimental session as you did suggest (I have tried it, but I still am unsure about all of this), is a single click a sufficient amount of change to feel the difference? Would it be reasonable to try large changes to feel a radical difference or will that just obscure the use of that setting?

One other issue I forgot to mention before is the general approach to adjusting suspension; as I understand it as soon as i adjust the springs I have to adjust the dampers accordingly (and vice versa) - how do I do that sanely and how do I know I'm not dialing in ridiculous combinations?...
Is it neccessary to watch the combinations of roll bar and spring/damper settings in the same way? Do I have to go for soft suspension and soft rollbar at the same time or can a combination of stiff suspension ans soft rollbar (or whatever else) make sense?

In most cases one click to an adjustment will be noticeable, though this varies between the cars (the Lotus and Brabham are quite picky, the BRM quite forgiving), and depends a bit on your experience reading how the car handles.  But by all means use larger changes if necessary, even going to the extremes (do this with teh front bar and quickly find the difference between under steer and oversteer);  but in some cases (differential settings) a large change can render the car so difficult to drive that you'll have trouble discerning exactly why it is difficult.  I would recommend the Ferrari or Cooper to get started, both are relatively easy to learn and neither display the idiosyncrasies of other cars, which can get in the way of learning general setups (the Ferrari is my favorite overall, it excels at nothing but is very good at everything;  it has better performance than the Cooper, though the latter is more forgiving in handling and setups).

If you must change spring rates you will definitely want to tweak the shocks again, stiffer springs will almost always require stiffer shocks, and vice versa.  But you can tweak shock settings all day with no need to alter spring rates.  The springs carry the weight of the car and control how much weight shift will occur (longitudinally, laterally, and diagonally), the shocks control how fast that weight shift will occur (softer shock = faster weight shift), the bars control lateral weight shift at the ends of the car.  The stiffness of the springs/shocks typically has little bearing on the stiffness of the bars; a simplistic view:  the springs are always active, even if the car is standing still, the shocks come into play when the car is moving, the bars become a factor when the car is not moving in a straight line (whether cornering or negotiating traffic).

There are no "ridiculous combinations" if the car is handling well, anything ridiculous would probably be so ill-handling you would quickly change it.  If something works for you, don't worry if a dozen others state they do it differently;  for every person who says the front bar should always be larger than the rear you'll find someone who says all their setups use the same size bars;  for every recommendation of a 30 power side differential setting there will be someone else saying 85 is the only way to go ... and they are all correct, because you setup your car so you can drive it well.  I guarantee if you download a dozen setups for a particular car at a particular track and try them all you may find a couple that are comfortable for you and a couple that make you wonder how anyone could complete a single lap with them, yet all these people will be doing similar laptimes.

And there is no set procedure for what to adjust first, everything interacts to a degree, and everyone has their preferences.  The first thing I set is fuel, since its weight is a major factor in such small light cars;  I prefer races of 45-60 minutes (about as long as my remaining brain cells can concentrate) so design my setups around 20-30 minutes of fuel.  Then, with just a couple of laps of fuel (so the car is very light), I go to the longest straight on the track and set top gear such that the tach doesn't quite redline.  Back to a "half race" of fuel and work on the lower gears, then shocks, tire pressure, and camber;  unless I have major balance problems the bars aren't adjusted til later.  Then I leave, and return the next day ...were my improving lap times due to becoming more familiar with the track/car or to the setup?  This is when I make final tweaks.

What you may notice is that, after creating setups for several tracks, all those setups have much in common (same shocks, differential, etc.);  use that to create a "base" setup which you can take to any new track and with a few laps and a few tweaks be ready to race.  This is historically accurate also, the real cars were rarely adjusted, it being assumed a good driver could adapt his driving to the different tracks with minimal changes to the car.  (We have it so much easier.)

#9 atumno

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Posted Sep 20 2013 - 07:39 AM

again thanks everyone for your help.

There is lot's of useful information here, and while I'm still pretty intimidated by the prospect of starting with the whole setup procedure at least i have some clues now how and where to start to look.

thanks for taking the time and the patience of explaining something that has been discussed over and over before already, I am aware of that, and I am really grateful. Hopefully someone else might find some useful hints in this topic also. I surely did!

#10 TvO - guest

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Posted Sep 20 2013 - 08:27 AM

What you can also do is download a bunch of setups from different people, have a look at where they are different, and try them out of the track to feel the changes between setups. For 1969, I use adjusted Greger Huttu 1967 setups with adjusted tire pressures and higher spring rate to suit the mod. I've noticed that the default setups made by Steve Cloyd used much higher spring rates, but lower damper settings than Gereger Huttus setups. Personally, I find the Huttu setups more predictable and stable, probably due to this.

#11 gabuck

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Posted Sep 20 2013 - 11:24 AM

I find this whole thread an interesting and informative read. I'm not a 'racer' as such and have always concentrated on personal bests for each car at each track, trying to learn how changes in settings influence my PBs.

Something I was surprised at is how little is mentionned about wheel camber. I've always followed the intuitive approach of trying to get a n even temperature profile across each tyre on the assumption that this implies the tyre is working equally across the tread and hence you are getting the greatest lateral forces from the tyres - the result of course is highly assymetric camber angles side to side.

If I think about it, there are strategic corners on circuits where a particularly fast exit allows you to carry speed out of the corner and make a disproportionate improvement in lap time, so maybe I should try to get the even temperature profile here and forget the average profile over the lap.

Does anyone have any views on this, or am I barking up the wrong tree about worrying about camber?

Geoff.

#12 jgf

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Posted Sep 21 2013 - 05:43 PM

Regarding camber, you actually want the temperatures slightly higher on the inside, then adjust pressure so the center temperature is midway between the inner and outer temperatures.  When cornering this places the outside tire almost vertical for best contact patch.  Typically the softer the suspension the more camber you'll need, and more on the front wheels than the rear (to aid with steering).  On fast circuits with a stiff suspension, front camber may be a mere .6 or so and the temperature spread across the tire only 4-5 degrees;  on twisty road courses with a soft suspension, front camber may be 1.5-2.0 (I've never gone beyond this, though some do) and the temperature spread around 15 degrees.  On most of my setups rear camber tends to be one third to one half of the front setting.

While many decried her setups as too stable or not fast enough, I found Alison Hine's setups, particularly the "X-Files", very good for beginners.  Once a mainstay of the GPL community, she is long gone (with a Cobra 427SC to race and a stunt plane to fly who would want to sit at a keyboard?).  But her website remains -
http://alison.hine.net/gpl/

Edited by jgf, Sep 21 2013 - 05:58 PM.


#13 Arturo Pereira

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Posted Sep 21 2013 - 06:59 PM

Alison is still pretty active in Facebook, though not related with racing afaik.

#14 jgf

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Posted Sep 21 2013 - 07:08 PM

lol, didn't mean to imply she had passed away, hence the parenthetic statement

#15 David Wright Lo67

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Posted Sep 22 2013 - 02:20 AM

View Postjgf, on Sep 21 2013 - 05:43 PM, said:

Regarding camber, you actually want the temperatures slightly higher on the inside, ...

In real life and other sims this is indeed the case.  If you apply negative camber to a tyre and drive in a straight line, the inside of the tyre will heat up more than the outer. However, GPL doesn't model un-even tyre heating when rolling in a straight line with camber.  Given this is the case, for GPL I'd suggest the traditional objective of even temperatures is probably the right approach.

#16 M Needforspeed

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Posted Sep 22 2013 - 02:45 AM

maybe not everyone posting here know about what Atumno has worked on, some years back .He contributed a lot for GPL

Please, Atumno, your thread here cld be a good opportunity to summarize what you did for us.at the moment, I found this

http://srmz.net/inde...=5935&hl=atumno

I use those great CD covers for all my back ups on CD of GPL movies and some other related stuff.


Thank you

Edited by M Needforspeed, Sep 22 2013 - 02:48 AM.


#17 John Woods

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Posted Sep 23 2013 - 08:15 AM

Atumno's on the Credits List?

He may have been gone awhile back when I started calling my setup philosophy "Too Loose To Wreck."

Edited by John Woods, Sep 23 2013 - 08:17 AM.


#18 atumno

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Posted Sep 24 2013 - 07:21 AM

hehe, thanks for the compliment, nice to see someone still remembers these covers. That's been a long while ago...
I never saw it as much of a contribution at all (It's all pretty insignificant stuff. some layout screens and a few cd-covers, that's about it.), esp since most of it again was based on other people's work (I mostly used screenshots I found on the rsc-forum). just sharing some stuff i fiddled with... (btw - I'm pretty sure the DVD shaped cover was not made by me, i think it might be nardin's work iirc...). I actually thought about setting up a small website a while ago to have all my gpl stuff online, but I never did it. (I wanted to include the gpl-movie I once made, but then I was afraid to run into trouble because of the music it uses...)

The real contributors (and those that deserve the credits) are those that improved the game with graphics, tracks, mods, tools, advice, etc., to an extend that we still can enjoy it today after 15 years.

Edited by atumno, Sep 26 2013 - 08:20 AM.


#19 John Woods

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Posted Sep 27 2013 - 12:37 PM

From the October 2013 issue of Car & Driver magazine, quoting from an interview with Russ Ruedisuell, Formula Ford racer and head of Chrysler SRT and motorsports engineering:

"If the driver is comfortable, you get better laptimes and better race results."

He agrees with Pete.

"We set the SRT stuff up so it can move around a bit, so you can drive a little bit with the throttle. We're proud of that. Our dynamics team, that put the basic package together, is all ex-racers. We're all anti-push; we'd rather have a little oversteer than understeer."




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